* Avi Kivity <avi@xxxxxxxxxx> wrote: > > Also, a profile of a typical kernel build shows: > > > > 0.69% cc1 [kernel.kallsyms] [k] clear_page_c > > 0.49% cc1 [kernel.kallsyms] [k] page_fault > > > > So while we could improve it, the question is, can we do this without > > accidentally slowing things down by more than 0.69%? And kernel > > builds are a pretty clear_page_c() intense workload. > > I usually see much higher clear_page_c, but I'm using a pretty old > system for most of my testing. Well, clear_page_c() is still the most expensive kernel function. I'd suggest using a modern system *and* using percise PEBS profiling via perf record -e cycles:pp - otherwise it's easy to see profiling artifacts, especially in and around short functions like clear_page_c(). Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
